61315257 has 4 divisors (see below), whose sum is σ = 81753680. Its totient is φ = 40876836.

The previous prime is 61315249. The next prime is 61315259. The reversal of 61315257 is 75251316.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 61315257 - 2³ = 61315249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61315259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10219207 + ... + 10219212.

It is an arithmetic number, because the mean of its divisors is an integer number (20438420).

Almost surely, 2^61315257 is an apocalyptic number.

It is an amenable number.

61315257 is a deficient number, since it is larger than the sum of its proper divisors (20438423).

61315257 is a wasteful number, since it uses less digits than its factorization.

61315257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20438422.

The product of its digits is 6300, while the sum is 30.

The square root of 61315257 is about 7830.4059281751. The cubic root of 61315257 is about 394.3267000070.

The spelling of 61315257 in words is "sixty-one million, three hundred fifteen thousand, two hundred fifty-seven".